The PCU1-SP mk2 is a medium powered primary current injection set offering output currents up to 5000A (11.5kVA for 40seconds). The system consists of a separate control unit containing all metering and control functions and a loading unit, such as the NLU200, NLU2000 or the NLU5000, that provides the high current output. The PCU1-SP mk2 are ideally suited to primary current injection, stability testing and circuit breaker testing. In addition, the SP version offers direct-reading CT ratio and polarity tests and a 100A secondary injection output. Two loading units are available, delivering a maximum output current of 2000A or 5000A. Each loading unit has three output taps to allow for a wide range of load impedances. For example, the NLU5000 may be configured to either give a maximum current of 5000A on the 2.3V range, 2500A on the 4.6V range or 1250A on the 9.2V range.
The control unit is rated at 11.5kVA with a 2 second overload capability of 23kVA using pulse mode. All metering is digital and a memory facility is provided to hold the current reading when the output trips or is switched off. The current is switched by a solid state device and is automatically switched off when the device under test trips.
The PCU1-SP systems have a high accuracy timing system, allowing timing tests to be carried out to a resolution of 1ms. Selection for normally open or normally closed contacts is automatic, and the status of the contacts is shown on the front panel. Timing modes are available to test under and over current devices, re-closers, under and over voltage devices, current trips and circuit breakers.
A full range of high current output leads are available to complement the system in a range of lengths.